Accidental mixing

Hypergolic A hypergolic mixture ignites upon contact of the components without any external source of ignition (heat or flame). The only field, in which this is a desirable event, is in rocket fuel research. Accidental mixing of incompatible materials can lead to a fire or explosion. Here is one example provided by the staff at ILPI of what can happen, when incompatibles are mixed. Always read the labels on your bottles (don t assume a chemical s identity by the shape, size, or color of the bottle), and know what materials are incompatible with the chemicals that you are using. 

The principal source of pollution by polybrominated biphenyls (PBBs) has been the commercial mixture Firemaster, which was produced in the United States between 1970 and 1974. Production was discontinued in 1974 following a severe pollution incident in Michigan, when Firemaster was accidentally mixed with cattle feed on a farm. In due course, PBBs entered the human food chain via contaminated animal products. Substantial residues were found in humans from the area, and were snbse-quently found to be highly persistent. 

The two compounds were accidentally mixed in a reactor because of similar packaging. They reacted uncontrollably, rupturing the reactor, and the evolved hydrogen ignited, killing one worker and injuring four. If as is probable a base catalyst was present depolymerisation/disproportionation to oxomethylsilane and methylsilane is also possible, with an increase in both vapour pressure and flammability. 

A violent reaction occurred which shattered the flask when litre quantities of dimethyl sulfate and cone, aqueous ammonia were accidentally mixed. Use dilute ammonia in small quantities to destroy dimethyl sulfate [1], Similar incidents were noted previously with ammonia and other bases [2],... 

Accidental mixing of the hot crude hydroquinone with cone, sodium hydroxide solution led to extensive exothermic decomposition. 

Accidental mixing of the 3 molten salts caused a violent explosion. 

Paper data in the form of operator logs, batch sheets, or additions sheets or logs may be particularly important if reactive chemistry is suspected. These may highlight the accidental mixing of incompatible materials, improper sequencing of additions, or improper addition rates or volumes. 

Accidental mixing of engineered plant material with food intended for human consumption or as feed for domestic animals ... 

Wear safety glasses. Do not use bleach products because they will oxidize the pigment, rendering it insensitive to any changes in pH. You also do not want to run the risk of accidentally mixing a bleach solution with the toilet bowl cleaner because... 

The polybrominated biphenyls (PBBs) were a disaster for the State of Michigan. PBBs were accidentally mixed into dairy cow feed in mid-1973, and as a result, the milk of much of the state became contaminated. As Michiganders consumed this milk, they too became contaminated. The history of this accident makes an interesting lesson and is summarized here based on the account by Fries [1]. 

In 1973 about 2000 lb of PBBs were accidentally mixed with livestock feed at the Michigan Farm Bureau feed mill in Battle Creek, Michigan—the result of packaging mix-up of "Firemaster" and "Nutrimaster", a sweetening agent (MgO) used in cattle feed. Thousands of animals sickened and died. Some 30,000 cattle, along with thousands... 

As Bob gazes into Miss Muxdroozol s azure eyes, he cannot help but think she is right. Could the creature in his room have been a fragment of a dream Bob has heard that the ship s food supply may have been temporarily infused with a low-dose hallucinogen. It was a mix-up. One of the alien races required the chemical for sustenance, and the cook had accidentally mixed it into the human supply. 

In most, though not all, cases there is no way that an average or sophisticated consumer could ever know, without scientific testing, that a non-authentic oil was not what it claimed to be. Indeed, at least with bulk food oils, such as corn, sunflower etc., a low level (e.g. 1%) of another oil being present would often be accepted in a product as being probably due to accidental mixing in the refining... 

The safe storage of adhesives and sealants that contain flammable, corrosive, or hazardous substances must also be considered. Many organic solvents are flammable, and certain adhesives will generate copious amounts of heat when reacted. For this reason, containers used for two- or three-part materials should be stored separately to prevent accidental mixing of the components in the case of spillage. 

Dowex 50 (H+ form)—Mix 1 kg of Dowex 50, X-8, 20 to 50 mesh, with 20 liters of dilute HC1 (3 liters of concentrated HC1 +17 liters of distilled water), stir for 5 min, fill with additional H20, and decant. Wash by decantation or suspension and vacuum filtration until the eluate no longer yields any titrat-able acidity (pH 3 to 4). Drain the resin until a moist paste is obtained. Each pair of students will need about 350 ml of moist Dowex 50. The resin should be collected at the end of the experiment (Do not allow accidental mixing with IR-45) and promptly regenerated by the above procedure. Store tightly covered under a water layer. (See note following IR-45 preparation.)... 

Do not allow your friends to mix things just to see what will happen. Do not do so yourself. Some combinations of chemicals are dangerous and you might accidentally mix some of these. Perform only the experiments for which you have complete instructions. 

Palanco and Laserna developed an instrument capable of reducing the quality assessment time in stainless steel factories by a factor of 25 [172]. The instrument performs LIBS-based quantitative analyses to check for the occurrence of accidental mixing during steel production, which may lead to incorrect shipping of the final products. Once again. 

Your company has been contacted by a fireworks factory. A mislabeled container of sodium chloride, NaCl, was accidentally mixed with potassium nitrate, KNO3. KNO3 is used as an oxidizer in fireworks to ensure that the fireworks burn thoroughly. The fireworks company wants your company to investigate ways they could separate the two compounds. They have provided an aqueous solution of the mixture for you to work with. 

A significant incident of environmental contamination by PBBs occurred in 1973-74 when approximately 650 pounds (290 kg) of FireMaster BP-6 (principally composed of 2,2, 4,4, 5,5 -hexabromobi-phenyl or P-153) were accidentally mixed with cattle... 

---